1. Field of the Invention
The present invention relates to a printed circuit board mounted electrical connector including a metal housing which forms, at an outer end thereof, a connecting opening for receiving a mating connector. The metal housing includes a pair of right and left side walls and at least one horizontal wall interconnecting the side walls. The side walls and the horizontal wall together enclose a terminal which can be connected directly to the mating connector.
2. Description of the Related Art
With continued reduction of the thickness of electronic apparatuses, it has been increasingly desired to mount a greater variety and number of component devices on the surface of a printed circuit board. In some cases, even such component as a connector jack for connection to a power source or an external instrument is mounted directly on the printed circuit board. However, unlike other devices such as circuit elements surface-mounted on the board, such thickness reduction is difficult for a connector jack or plug. This difficulty results in hampering the desired thickness reduction of the entire printed circuit board or the electronic apparatus as a whole.
In order to solve the above problem, according to e.g. a printed circuit board mounted connector disclosed by the Japanese utility model application laid open under No. Hei. 1-161583, the printed circuit board is provided with a board segment forming a terminal land for connection to an external instrument. Further, a resin housing which is configured to be detachably attachable is attached to the circuit board in such a manner as to enclose the board segment. In use, a terminal of a jack or a plug as a mating connector is contacted with the terminal land for establishing required electrical connection. With this connector construction, the terminal of the mating connector and the terminal land of the board segment are directly connected to each other as described above. Hence, it is possible to omit such additional components as a contact for relaying the electrical connection between the terminal and the terminal land or a retaining element for retaining the connection and to omit manufacture, assembly or soldering associated with and required by such additional components. Hence, it is relatively easy to achieve reduction in cost and size of the connector.
Notwithstanding the above, the conventional connector construction suffers a problem as follows. Namely, in this connector construction, in order to prevent inadvertent detachment of the housing from the circuit board, the housing includes at a deep inner portion thereof, a projection engageable into an associated hole defined in the circuit board. This projection may be subjected to a concentrated stress during insertion or removal of the connector to or from the mating connector, often resulting in fracture of the projection. In order to avoid this, it is necessary to provide adequate reinforcement in the periphery of the projection. Such reinforcement, however, will again hinder the desired thickness reduction of the printed circuit board mounted connector.
The prior art has proposed another printed circuit board mounted connector disclosed by Japanese patent application laid open under No. Hei. 10-270107. This connector includes a body as a housing which can be attached to a cutout defined at a base end of the printed circuit board. The body includes a retained portion to be retained to a jack or a plug of the mating connector, and a binding portion for vertically binding the circuit board for retaining the board in the thickness direction thereof. The body further includes an engaging element engageable with a locking cutout portion formed within a cutout of the printed circuit board. In use of this surface mounted connector, the binding portion acts to support the thickness-wise center of the housing (body) to the printed circuit board, so that the projecting height of the connector relative to the circuit board is divided into one portion projecting upward from the front side of the board and the other portion projecting downward from the back side of the same.
However, this printed circuit board mounted connector also suffers the same problem as the first type mentioned above. Namely, in order to effectively withstand the force which may be applied in any direction in association with insertion or removal of the mating connector jack or plug, reinforcement is needed, particularly for the engaging element. In any case, the constructions of the retaining portions of these conventional connectors do not contribute to desired thickness reduction of the printed circuit board amounted electrical connector.
Hence, a primary object of the present invention is to provide a printed circuit board mounted electrical connector which can effectively withstand a force which may be applied thereto in any direction in association with insertion or removal of the jack or plug of the mating connector and which also can contribute to the thickness reduction of the connector.
For fulfilling the above-noted object, according to the present invention, a printed circuit board mounted electrical connector comprises a metal housing which forms, at an outer end thereof, a connecting opening for receiving a mating connector. The metal housing includes a pair of right and left side walls and at least one horizontal wall interconnecting the side walls. The side walls and the horizontal wall together enclose a terminal which is formed at a portion of the circuit board and which can be connected directly to the mating connector. The connector further comprises a fixing piece extending from each of the side walls, the fixing piece having an attaching face configured to be placed on and solder-fixed to a solder attaching land formed in the circuit board.
With this construction, the housing defining the connecting opening into or from which the jack or plug of the mating connector is inserted or removed is formed of metal and this metal housing integrally forms the fixing pieces described above. Therefore, even if the connector is formed thin, the connector can still provide sufficient strength for withstanding a force applied thereto in association with insertion or removal of the mating connector. Especially, as the fixing pieces provided to the metal housing are placed and solder-fixed to the solder attaching land of the circuit board, the housing can be fixed in position in a secure manner. Moreover, such fixing by means of soldering requires relatively short height, thus not hindering desired thickness reduction of the connector.
According to one preferred embodiment of the invention, said terminal to be connected to the mating connector is provided in the form of a terminal land formed on a board segment extending from the circuit board. This construction provides an advantage of allowing the terminal to be formed integrally with the circuit board.
According to another preferred embodiment, each said side wall includes at least one binding portion for binding the front and back sides of the circuit board. With this construction, as the binding portions for vertically binding the circuit board are formed in the metal housing having high strength, formed preferably integrally therewith, the binding portions, even when formed thin, can still provide sufficient strength. Further, if a pair of such binding portions are provided respectively at the proximal end and the distal end of the housing, this arrangement will further strengthen the attachment of the housing to the circuit board. Advantageously, an entrance area of a board inserting slot of the binding portion may be provided with an increased width for guiding or facilitating its insertion into the circuit board. In this case, if the width of the remaining portion of the board inserting slot is adapted to correspond to the thickness of the circuit board, the binding portion may be firmly retained without looseness.
According to a still further embodiment of the invention, the housing further includes a bottom wall at an inner end thereof, the bottom wall defining an insertion opening for allowing insertion of the board segment.
With this construction, the metal housing includes the bottom wall and this bottom wall defines an insertion opening for the board segment. Hence, the metal housing is provided substantially in the form of a box having even higher strength. Further, if the binding portion for binding the board segment inserted into the insertion opening is provided in the form of a slot extending continuously from an insertion opening defined at an end of the side wall of the housing, it becomes possible to minimize the opening which may allow entrance of a foreign object into the housing.
Further, if the housing is provided in the form of an angular tube formed of the opposed side walls and a pair of upper and lower horizontal walls, a spacer made of dielectric material may be interposed between the board segment inserted into the housing and the upper horizontal wall and between the board segment and the lower horizontal wall, respectively. This arrangement provides the advantage of restricting unnecessary displacement between the board segment and the housing. Moreover, if this spacer is configured so as to close the inner space of the housing, the spacer may act as a xe2x80x9cbarrierxe2x80x9d for preventing entrance of foreign object into the housing.
According to still another preferred embodiment of the present invention, a printed circuit board mounted electrical connector comprises a metal outer housing having a pair of right and left side walls and at least one horizontal wall interconnecting the side walls, an inner housing accommodated and held within the outer housing, a connecting opening defined at an outer end of the outer housing for receiving a mating connector, and a terminal base having a contact capable of directly contacting the mating connector, the terminal base being enclosed and held within the inner housing; wherein the outer housing includes at least one binding portion for binding front and back faces of the circuit board and from each of the side walls, there extends a fixing piece having an attaching face configured to be placed on and solder-fixed to a solder attaching land formed in the circuit board.
In the case of this connector construction, the housing consists of an outer housing and an inner housing, and the binding portion and the fixing piece are formed in the metal outer housing, not in the inner housing which is generally formed of e.g. a resin material. Therefore, even when the construction is formed thin, the construction yet provides sufficient strength for withstanding the force generated in association with insertion or removal of the mating connector. Consequently, it is possible to restrict mechanical looseness of the housing relative to the circuit board and also to prevent inadvertent detachment of the solder-connected portion for the electrical connection between this connector and the circuit board or breakage of the body of the connector as well. That is, as the binding portion for vertically binding the circuit board is provided in the metal outer housing which has greater strength than the inner housing formed generally of resin or the like, the binding portion, even when formed thin, can provide sufficient strength against the force applied externally thereto. Moreover, as the fixing piece also provided in this outer metal housing is placed and solder-fixed to the solder attaching land of the circuit board, the metal outer housing can be securely fixed to the circuit board. In addition, since such fixing by means of soldering requires relatively short height, as compared with other mode of fixing using a screw for instance, this construction can contribute to the goal of thickness reduction of the printed circuit board amounted electrical connector. The binding portion may be formed on the side of each side wall adjacent the Circuit board or on the side thereof distant therefrom, depending on the required attachment strength. The binding portion may be readily formed for example by defining a slit corresponding to the thickness of the circuit board in the side wall of the outer housing.
The binding portion may be formed by defining a slit having a width corresponding to the thickness of the circuit board at an end of each of the right and left side walls of the outer housing. Alternatively, this binding portion may be formed by bending a portion of the right and left side walls of the outer housing to form a rib or the like and then defining a slit in this rib or the like. In any case, when compared with a construction in which a separate binding portion or member is attached to the outer housing, the above proposed integral constructions achieve the advantage of reducing the number of elements required and correspondingly reducing the number of steps required for the assembly of the construction.
Further and other features and advantages of the present invention will become apparent from the following detailed disclosure with reference to the accompanying drawings.